diff options
Diffstat (limited to 'editor/specialty/ppmspread.c')
| -rw-r--r-- | editor/specialty/ppmspread.c | 206 |
1 files changed, 132 insertions, 74 deletions
diff --git a/editor/specialty/ppmspread.c b/editor/specialty/ppmspread.c index 6753f4fe..7b9558e3 100644 --- a/editor/specialty/ppmspread.c +++ b/editor/specialty/ppmspread.c @@ -10,102 +10,158 @@ #include <string.h> +#include "nstring.h" +#include "rand.h" +#include "shhopt.h" #include "ppm.h" +struct CmdlineInfo { + /* This structure represents all of the information the user + supplied in the command line but in a form that's easy for the + program to use. + */ + const char * inputFilename; /* '-' if stdin */ + unsigned int spread; + unsigned int randomseedSpec; + unsigned int randomseed; +}; + + + +static void +parseCommandLine(int argc, const char ** const argv, + struct CmdlineInfo * const cmdlineP ) { + + optEntry * option_def; + /* Instructions to OptParseOptions3 on how to parse our options */ + optStruct3 opt; + unsigned int option_def_index; + + MALLOCARRAY_NOFAIL(option_def, 100); + option_def_index = 0; /* Incremented by OPTENTRY */ + + OPTENT3(0, "randomseed", OPT_UINT, &cmdlineP->randomseed, + &cmdlineP->randomseedSpec, 0); + + opt.opt_table = option_def; + opt.short_allowed = 0; + opt.allowNegNum = 1; + + pm_optParseOptions3( &argc, (char **)argv, opt, sizeof(opt), 0 ); + + if (argc-1 < 1) + pm_error("You must specify the spread factor as an argument"); + else { + const char * error; + pm_string_to_uint(argv[1], &cmdlineP->spread, &error); + + if (error) + pm_error("Spread factor '%s' is not an unsigned integer. %s", + argv[1], error); + + if (argc-1 < 2) + cmdlineP->inputFilename = "-"; + else { + cmdlineP->inputFilename = argv[2]; + if (argc-1 >2) + pm_error("Too many arguments: %u. " + "The only possible arguments are " + "the spread factor and the optional input file name", + argc-1); + } + } +} + + + +static void +spreadRow(pixel ** const srcarray, + unsigned int const cols, + unsigned int const rows, + unsigned int const spread, + unsigned int const row, + pixel ** const destarray, + struct pm_randSt * const randStP) { + + unsigned int col; + + for (col = 0; col < cols; ++col) { + pixel const p = srcarray[row][col]; + + int const xdis = (pm_rand(randStP) % (spread + 1) ) + - ((spread + 1) / 2); + int const ydis = (pm_rand(randStP) % (spread + 1)) + - ((spread + 1) / 2); + + int const xnew = col + xdis; + int const ynew = row + ydis; + + /* only set the displaced pixel if it's within the bounds + of the image + */ + if (xnew >= 0 && xnew < cols && ynew >= 0 && ynew < rows) { + /* Displacing a pixel is accomplished by swapping it + with another pixel in its vicinity. + */ + pixel const p2 = srcarray[ynew][xnew]; + /* Original value of second pixel */ + + /* Set second pixel to new value */ + PPM_ASSIGN(destarray[ynew][xnew], + PPM_GETR(p), PPM_GETG(p), PPM_GETB(p)); + + /* Set first pixel to (old) value of second */ + PPM_ASSIGN(destarray[row][col], + PPM_GETR(p2), PPM_GETG(p2), PPM_GETB(p2)); + } else { + /* Displaced pixel is out of bounds; leave the old pixel there. + */ + PPM_ASSIGN(destarray[row][col], + PPM_GETR(p), PPM_GETG(p), PPM_GETB(p)); + } + } +} + + int -main(int argc, - char * argv[]) { +main(int argc, + const char * argv[]) { + struct CmdlineInfo cmdline; FILE * ifP; - int argn, rows, cols; + int rows, cols; unsigned int row; - pixel ** destarray, ** srcarray; - pixel * pP; - pixel * pP2; + pixel ** destarray; + pixel ** srcarray; pixval maxval; - pixval r1, g1, b1; - int amount; - const char * const usage = "amount [ppmfile]\n amount: # of pixels to displace a pixel by at most\n"; - - /* parse in 'default' parameters */ - ppm_init(&argc, argv); - - argn = 1; - - /* parse in amount & seed */ - if (argn == argc) - pm_usage(usage); - if (sscanf(argv[argn], "%d", &amount) != 1) - pm_usage(usage); - if (amount < 0) - pm_error("amount should be a positive number"); - ++argn; - - /* parse in filename (if present, stdin otherwise) */ - if (argn != argc) - { - ifP = pm_openr(argv[argn]); - ++argn; - } - else - ifP = stdin; + struct pm_randSt randSt; - if (argn != argc) - pm_usage(usage); + pm_proginit(&argc, argv); + + parseCommandLine(argc, argv, &cmdline); + + ifP = pm_openr(cmdline.inputFilename); srcarray = ppm_readppm(ifP, &cols, &rows, &maxval); destarray = ppm_allocarray(cols, rows); + pm_randinit(&randSt); + pm_srand2(&randSt, cmdline.randomseedSpec, cmdline.randomseed); + /* clear out the buffer */ for (row = 0; row < rows; ++row) memset(destarray[row], 0, cols * sizeof(pixel)); - srand(pm_randseed()); - - /* start displacing pixels */ + /* Displace pixels */ for (row = 0; row < rows; ++row) { - unsigned int col; - pP = &srcarray[row][0]; - - for (col = 0; col < cols; ++col) { - int const xdis = (rand() % (amount+1)) - ((amount+1) / 2); - int const ydis = (rand() % (amount+1)) - ((amount+1) / 2); + spreadRow(srcarray, cols, rows, cmdline.spread, row, + destarray, &randSt); - int const xnew = col + xdis; - int const ynew = row + ydis; - - /* only set the displaced pixel if it's within the bounds - of the image - */ - if (xnew >= 0 && xnew < cols && ynew >= 0 && ynew < rows) { - /* displacing a pixel is accomplished by swapping it - with another pixel in its vicinity - so, first - store other pixel's RGB - */ - pP2 = &srcarray[ynew][xnew]; - r1 = PPM_GETR(*pP2); - g1 = PPM_GETG(*pP2); - b1 = PPM_GETB(*pP2); - /* set second pixel to new value */ - pP2 = &destarray[ynew][xnew]; - PPM_ASSIGN(*pP2, PPM_GETR(*pP), PPM_GETG(*pP), PPM_GETB(*pP)); - - /* now, set first pixel to (old) value of second */ - pP2 = &destarray[row][col]; - PPM_ASSIGN(*pP2, r1, g1, b1); - } else { - /* displaced pixel is out of bounds; leave the old - pixel there - */ - pP2 = &destarray[row][col]; - PPM_ASSIGN(*pP2, PPM_GETR(*pP), PPM_GETG(*pP), PPM_GETB(*pP)); - } - ++pP; - } } + pm_randterm(&randSt); ppm_writeppm(stdout, destarray, cols, rows, maxval, 0); @@ -115,3 +171,5 @@ main(int argc, return 0; } + + |